Multibreak metal-clad puffer type circuit interrupter having staggered arc-extinguishing units

ABSTRACT

A multibreak puffer type circuit interrupter having a cylindrical metal enclosure filled with compressed gas, such as sulfur hexafluoride. Longitudinal beams extend in the enclosure to support a plurality of transverse support plates forming partition walls defining therebetween a number of sections housing the different arc-extinguishing units. The units of odd rank are aligned on a first axis and the units of even rank are aligned on a second axis, both axes being symmetrically offset from the axis of the enclosure. The exhaust ends of the units are laterally juxtaposed to the puffer mechanism of the nextfollowing units so as to obtain an overlapping of the units permitting to reduce the overall length of the pole.

United States Patent 1191 Okerman et al.

11] 3,895,202 [451 July 15,1975

[ MULTIBREAK METAL-CLAD PUFFER TYPE CIRCUIT INTERRUPTER HAVING STAGGEREDARC-EXTINGUISI-IING UNITS [73] Assignee: Societe Anonyme of MerlinGerin,

Grenoble, France [22] Filed: June 14, 1974 [21] Appl. No.: 479,511

[30] Foreign Application Priority Data June 28, 1973 France 73.23817[52] U.S. Cl. 200/148 A; 200/145; 200/144 AP FOREIGN PATENTS ORAPPLICATIONS 872,753 v 2/1942 France 200/145 892,082 l/l944 France200/145 466,553 5/1937 United Kingdom 200/145 Primary Examiner-Robert S.Macon Attorney, Agent, or Firm-Stevens, Davis, Miller & Mosher 5 7ABSTRACT A multibreak puffer type circuit interrupter having acylindrical metal enclosure filled with compressed gas, such as sulfurhexafluoride. Longitudinal beams extend in the enclosure to support aplurality of transverse support plates forming partition walls definingtherebetween a number of sections housing the differentarc-extinguishing units. The units of odd rank are aligned on a firstaxis and the units of even rank are Int. CI. n d d b r I gne on a seconaxis, oth axes being symmetri- [5 8] F'eld Search 200/148 145 144 APcally offset from the axis of the enclosure. The exhaust ends of theunits are laterally juxtaposed to the puffer [56] References Cnedmechanism of the next-following units so as to obtain UNITED STATESPATENTS an overlapping of the units permitting to reduce the 2,913,55611/1959 Leeds 200/148 A overall length of the pole. 2,979,591 4/1961Friedrich 200/148 A I 3,300,609 1/1967 Flurscheim et al. 1. 200/145 3Clam! 6 Drawmfl 8 4 O ee fATENTEDJUL 15 1915 3.895; 202

" SHEET 1 SHEET FIG.2

5. ,m m? M 3 mm zis F. I.

2 i4 213 A y 1/, BRM A 8% l 1.2 kifiiv MULTIBREAK METAL-CLAD PUFFER TYPECIRCUIT INTERRUPTER HAVING STAGGERED ARC-EXTINGUISI-IING UNITS Thisinvention relates to high-voltage metal-clad multibreak circuitinterrupters and more particularly to a pole of such circuitinterrupters having a plurality of electrically series-connectedarc-extinguishing chambers in which an arc is drawn between a pair ofseparable contacts whereby a blast of compressed arcextinguishing gas isdirected to the arc in order to quench the latter.

In known circuit interrupters of this kind, the differentarc-extinguishing units are housed in a metal grounded enclosure ofgenerally cylindrical shape filled with a compressed gas having a higharc-extinguishing power and a high dielectric strength, such as sulfurhexafluoride. The high-voltage metalclad circuit interrupters of theprior art operate at dual pressure and need therefore a costlycompressor station to deliver the arc-extinguishing gas at a relativelyhigh pressure. On the other hand, the different arc-extinguishing unitsof a pole are aligned on a common axis so that the total length of thepole is important and increases again the cost of the installation.

It is an object of the invention to provide a singlepressure multibreakmetal-clad circuit interrupter having a simple and rugged constructionof reduced length and of modular design permitting to assemble circuitinterrupters of different voltage ratings by simple adding of removingof standardized parts, more particularly of standardizedarc-extinguishing units together with the support elements thereof.

These and other objects and advantages will become apparent upon readingof the now following description of some embodiments of the inventiongiven by way of example only and represented in the annexed drawings, inwhich:

FIG. 1 is a schematic side elevational view of a pole of a circuitinterrupter according to the invention, the outer casing being shown inaxial cross section and the control box being shown partially brokenaway;

FIG. 2 is a front elevational view of the pole according to FIG. 1, thecasing being again shown in cross section;

FIG. 3 is a schematic plan view wherein the top cover of the casing hasbeen removed;

FIG. 4 is a cross sectional view on an enlarged scale of an arcextinguishing device utilized in the circuit interrupter shown in FIG.1;

FIG. 5 shows the electric circuit diagram of an embodiment of theinvention comprising auxiliary circuit opening and/or closing resistors;and

FIG. 6 is a view similar to that of FIG. 3, showing schematically thearrangement of the resistors of FIG. 5.

In the FIGS., a cylindrical metallic pressure enclosure or outer casing10 comprises a pair of lateral cylindrical projections 12, 14 which arevertically spaced apart and support through generally cone-shapedinsulators 16, 18 axial conductors 20, 22, respectively, constitutinginput and output connections or bushings to connect the electricallyseries-connected arcextinguishing devices of the circuit interrupter toan external circuit or network. A top cover 26 and a bottom cover 24 areremovably bolted to the end portions of the casing 10 in a gastightmanner and the casing is filled with a compressed gas of higharc-extinguishing and dielectric power, such as sulfur hexafluoride of,for example 3.5 bars. The cylindrical enclosure 10 shown in the FIGS. isarranged vertically but it is of course also possible to dispose thecasing horizontally on a pedestal 28, the whole being in either case onearth potential.

The different elements of the multibreak pole unit located within theenclosure 10 are supported by a pair of longitudinally extending beamsof insulating material 30, 32 which are secured to the covers 24, 26 bybolts 34. A plurality of circular partition plates or discs ofconductive material 36, 38, 40, 42, 44 are spaced apart along the beams30, 32 and secured thereto in an appropriate manner. The end plates 36,44 are aligned with the bushings 20, 22, respectively, and electricallyconnected thereto through plug-in connections 46, 48, respectively. Theintermediate plates 38, 40, 42 are regularly spaced apart along thebeams 30, 32 so as to define four successive sections 50, 52, 54, 56,each of which corresponds to a breaking interval of the pole whichcomprises on the whole four breaking points, in the example shown. Thedistance between the plates 36 to 44 is of course adapted to therequired insulation level for compressed sulfur hexafluoride.

The arc-extinguishing devices which are electrically series-connectedand located in the respective sections 50, 52, 54, 56 are of the puffertype and identical so that only one of them, associated with the section56, will now be described in more detail with reference to FIG. 4.

The arc-extinguishing unit comprises two distinct parts, one of which issupported by the plate 44 and associated with a stationary contact 60while the other, 62, is supported by the adjacent plate 42 andassociated with a movable contact 64 equipped with a puffer devicehaving a cylinder 66 and a piston 68. The part 62 is well known so thatit suffices to recall that the movable cylinder 66, which is rigidlysecured to the movable contact 64, slides on the stationary piston 68,which is supported by the plate 42, so that the gas confined between theconfronting wall portions of the cylinder 66 and the piston 68 can becompressed by a downward movement (with respect to FIG. 4) of thecontact 64 and of the cylinder 66 in order to direct a blast of gasthrough the orifice 70 in the direction of the are drawn between theseparating contacts. The parts 58 is also well known and comprises astationary contact 60 cooperating with a plurality of rear openings 72exhausting the blast gas. The arcing contacts 64 and 60 are shown solidbut may also be hollow. Preferably, main contacts 74, 76 are. associatedwith the arcing contacts to ensure the electric continuity in closedposition of the circuit interrupter. The part 58 traverses a centralhole 78 of the plate 44 so as to project therefrom on both sides of theplate so that the contacts 60, 76 are arranged on one side of the plate44 in confronting relation with the part 62, and the exhaust opening-member 72 on the opposite side of the plate 44. The

movable elements of the part 62 are actuated by means of a pair ofcontrol rods 80, 82 secured to the cylinder 66.

The four breaking devices are arranged in two groups, the devices of oddrank 84, 86 being essentially located in the sections 50, 54,respectively, and the elements of even rank 88, 90 extendingsubstantially within the sections 52, 56, respectively. The devices 84,

86 of odd rank are aligned on a first axis 92 (FIG. 3) which islaterally offset with respect to the axis of the cylindrical enclosureand the devices 88, 90 of even rank are aligned on a second axis 94which is also offset with respect to the axis of the cylinder, both axes92, 94 being symmetrical with respect to the axis of the cylinder 10.The off-centering of the axes 92, 94 is sufficient to permit thejuxtaposition on each intermediate plate 38, 40, 42 of a part 62 and ofa part 58 pertaining to the arc-extinguishing devices 84, 88; 88, 86',and 86, 90, respectively. The staggering of the devices 84 to 90 permitsan overlapping of adjacent devices and thereby a reduction of theoverall length of the pole. The conducting plates 36, 38, 40, 42, 44ensure the electrical connection between the contacts and the input andoutput conductors 20, 22, on the one hand, and between the movable andstationary contacts of successive arc-extinguishing devices, on theother hand. Voltage-dividing condensors 96 may advantageously beinserted between successive plates 36 to 44 in a wellknown manner.

The movable contacts and the puffer mechanisms of the arcextinguishing-devices of even rank 88, 90 are mechanically actuated bythe two rods 80, 82 which are in turn actuated by a control rod 98 whichis directly connected thereto or indirectly through the movable elementsof the arc-extinguishing device 88. The control rod 98 traverses thebottom cover 24 in a gastight manner and projects into a control box100. Similarly, the movable elements of the arc-extinguishing devices ofodd rank 84, 86 are actuated by a pair of control rods 102, 104 whichare in turn actuated by a control rod 106 which extends parallelly tothe control rod 98 and protrudes also, after having traversed the cover24 in a gastight manner, into the control box 100. Thus, the control rod98 actuates the devices 88, 90 and the control rod 106 the devices 84,86. Each control rod 98, 106 may have an individual driving mechanismbut in the embodiment shown in the FIGS, a hydraulic operating cylinderdevice 108 having a return spring (not shown) actuates the two controlrods 98, 106 may have an individual driving mechanism but in theembodiment shown in the FIGS, a hydraulic operating cylinder device 108having a return spring (not shown) actuates the two control rods 98,106. In this manner, the control of the rods 98, 106 is automaticallysynchronized so that all the contacts of the different devices opensimultaneously.

The operation of the above described circuit interrupter will beapparent. Suffice it to say that the blast gas which is compressed bythe puffer mechanism in order to be directed towards the arcs betweenthe different separating contacts is drawn from the lowpressureenclosure 10. The gas is subsequently exhausted in regions spacedrelatively far away from the breaking intervals. As a result, theoverlapping of the devices does not affect the insulating level of thepole.

The active parts of the pole are formed by standardized elements whichpermit a modular construction of a range of circuit interrupters ofdifferent ratings. Thus it is possible to provide a pole having only twoarcextinguishing units in which case only three connecting plates arenecessary. With an increasing number of units only the total length ofthe metal enclosure 10 needs to be adapted to the overall length of theoverlapping units. The inner equipment of the enclosure, comprising theinsulating support beams 30, 32 and the cross plates 36 to 44 with thearc-extinguishing units, constitutes a rigid assembly which can bewithdrawn as a unit from the enclosure 10 in order to permit maintenanceand exchange operations. The grounding of the metal-clad apparatusensures the safety of the installation.

The staggering of the arc-extinguishing units between the respectivecross plates lends itself particularly well to the incorporation ofcircuit-opening and/or -closing resistors associated with auxiliaryinterrupters the operation of which is suitably shifted forward or backin 7 time with respect to the operation of the main contacts in awell-known manner. FIGS. 5 and 6 show diagrammatically an embodiment ofthe invention comprising resistors of the kind mentioned.

In FIG. 5, the main contacts of each unit 84, 88, 86, are shunted by aseries-connection of a resistor 110, H4, 1 18, 122 with an auxiliaryinterrupter 112, 116, 120, 124, respectively. Advantageously, theresistorinterrupter units 110 to 124 are staggered along two parallelaxes 126, 128 visible on FIG. 6, and imbricated between the condensors96. The coaxial auxiliary interrupters 112, and 116, 124 are actuated ina manner similar to that of the main arc-extinguishing devices by a pairof auxiliary control rods (not shown) having a lowermost end portionextending within the control box 100. The central control within thecontrol box 100 permits to obtain in a simple manner any desiredsequence of the operation of the different auxiliary and main contacts.The resistor-interrupter units may all be coaxial or arranged along twoor more axes.

What we claim is:

l. A multibreak arc-extinguishing pole unit for a high-voltagemetal-clad puffer type circuit interrupter, comprising:

a grounded metal enclosure of substantially cylindrical shape adapted tocontain a compressed arcextinguishing gas of high dielectric strength;

a plurality of electrically series-connected arcextinguishing unitsspaced apart in said enclosure in the longitudinal direction thereof,each unit having a pair of elongated separable contact means extendingparallelly to said longitudinal direction to draw an arc therebetween,and a puffer mechanism coaxial with said contact means and adapted todraw gas from the inside of said enclosure to direct a blast ofcompressed gas on said arc, said contact means comprising a relativelystationary contact and a movable contact; said puffer mechanismincluding relatively movable piston and cylinder means arranged at oneend of the corresponding arc-extinguishing unit adjacent said movablecontact and vent opening means arranged at the opposite end of the unitadjacent said relatively stationary contact to exhaust said blast of gasinto said enclosure,

support beam means extending in said longitudinal direction within saidenclosure,

a plurality of transverse partition plates extending perpendicularly tosaid longitudinal direction and secured to said support beam means atregular intervals to define a 'number of sections therebetweencorresponding to the number of arcextinguishing units,

control rod means extending in said enclosure parallelly to saidlongitudinal direction to actuate said 6- movable contact and saidpiston and cylinder extinguishing unit is juxtaposed to said piston andmeans; cylinder means of the unit of next-higher rank so said contactmeans and said puffer mechanisms of that said units overlap each otherlaterally thereby the arc-extinguishing units of odd rank being reducingthe overall length of the assembled units aligned along a first axis andsaid contact means 5 of the pole. and said puffer mechanisms of the arc-.2. A circuit interrupter according to claim 1, further extinguishingunits of even rank being aligned comprising a plurality ofvoltage-dividing condensors along a second axis, said axes extendingparallelly inserted between said transverse plates.

to said longitudinal direction symmetrically with 3. A circuitinterrupter according to claim 1, further respect to the axis of saidcylindrical enclosure, 10 comprising a plurality of series-connectedresistor and said transverse plates supporting said units in such aauxiliary interrupter means inserted between said mannerthat in allsections but the first said vent transverse plates.

opening means of the corresponding arc-

1. A multibreak arc-extinguishing pole unit for a high-voltagemetal-clad puffer type circuit interrupter, comprising: a grounded metalenclosure of substantially cylindrical shape adapted to contain acompressed arc-extinguishing gas of high dielectric strength; aplurality of electrically series-connected arc-extinguishing unitsspaced apart in said enclosure in the longitudinal direction thereof,each unit having a pair of elongated separable contact means extendingparallelly to said longitudinal direction to draw an arc therebetween,and a puffer mechanism coaxial with said contact means and adapted todraw gas from the inside of said enclosure to direct a blast ofcompressed gas on said arc, said contact means comprising a relativelystationary contact and a movable contact; said puffer mechanismincluding relatively movable piston and cylinder means arranged at oneend of the corresponding arcextinguishing unit adjacent said movablecontact and vent opening means arranged at the opposite end of the unitadjacent said relatively stationary contact to exhaust said blast of gasinto said enclosure, support beam means extending in said longitudinaldirection within said enclosure, a plurality of transverse partitionplates extending perpendicularly to said longitudinal direction andsecured to said support beam means at regular intervals to define anumber of sections therebetween corresponding to the number ofarcextinguishing units, control rod means extending in said enclosureparallelly to said longitudinal direction to actuate said movablecontact and said piston and cylinder means; said contact means and saidpuffer mechanisms of the arcextinguishing units of odd rank beingaligned along a first axis and said contact means and said puffermechanisms of the arc-extinguishing units of even rank being alignedalong a second axis, said axes extending parallelly to said longitudinaldirection symmetrically with respect to the axis of said cylindricalenclosure, said transverse plates supporting said units in such a mannerthat in all sections but the first said vent opening means of thecorresponding arc-extinguishing unit is juxtaposed to said piston andcylinder means of the unit of next-higher rank so that said unitsoverlap each other laterally thereby reducing the overall length of theassembled units of the pole.
 2. A circuit interrupter according to claim1, further comprising a plurality of voltage-dividing condensorsinserted between said transverse plates.
 3. A circuit interrupteraccording to claim 1, further comprising a plurality of series-connectedresistor and auxiliary interrupter means inserted betWeen saidtransverse plates.